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Biomedical subjects

R Matalon

Publications and source records attributed to R Matalon.

At least 127 records · Page 7Linked to original sources
PubMed1976

The mucopolysaccharidoses (a review).

The mucopolysaccharidoses are a group of genetic diseases characterized by storage of incompletely degraded glycosaminoglycans. Such storage causes marked distortion of many tissues with consequent severe somatic changes and mental retardation. Storage of glycosaminoglycans results from markedly diminished activity of specific hydrolases requisite for the normal degradation of glycosaminoglycans. The specific enzymic defects have been identified in nine different diseases. In some cases evidence has been obtained indicating the existence of additional allelic diseases based on the same enzyme. The knowledge obtained from these studies has made prenatal diagnosis possible and has led to the possibility that therapy may be undertaken utilizing enzyme replacement.

Acetylglucosaminidase↗
PubMed1975

A new mucolipidosis with psychomotor retardation, corneal clouding, and retinal degeneration.

A 23-year-old man had slow psychomotor development at 6 months of age and developed intermittent corneal clouding at about 18 months. He developed a truncal ataxia and hypotonia of the limbs combined with spasticity and active deep reflexes that did not progress. His skeleton and facies were normal. Between 1 and 13 years of age, he developed severe optic atrophy, absence of retinal blood vessels, and an extinguished electroretinogram. Biochemical analysis of cultured fibroblasts indicated no lysosomal hydrolase deficiency; cellular metachromasia was absent and there was no mucopolysaccharidoses. Ultrastructural studies indicated single-membrane-limited vacuoles containing lamellated membranes and a polymorphous substance in tissue-cultured cells and conjunctiva.

Adolescent↗
PubMed1975

Glycopeptide storage in skin fibroblasts cultured from a patient with alpha-mannosidase deficiency.

Patients with mannosidosis, an inherited deficiency of lysosomal alpha-mannosidase, accumulate large amounts of mannose-rich oligosaccharides (the "core" of the carbohydrate units of many glocoproteins) in brain and liver and excrete these partial degradation products in their urine. A profound alpha-mannosidase deficiency was demonstrated in fibroblasts cultured from a skin biopsy obtained from a child with mannosidosis. Further, abnormal glycopeptides rich in mannose and similar to oligosaccharides found in the patient's urine were isolated from fibroblast extracts by a variety of chromatographic procedures and by virtue of their binding to a concanavalin A-Sepharose 4B affinity column. This storage material contained mannose, N-acetylglucosamine, and asparagine in the ratio 3 : 1 : 1 together with a few toher amino acids and had a molecular weight of approximately 1,100. There was no evidence for excretion of storage material by mannosidosis fibroblasts or for any abnormality in cell surface glycoprotein composition. The glycopeptide nature of the storage material isolated from cultured skin fibroblasts may be attributed to the low level of N-aspartyl-beta-glucosamindase (EC 3.5.1.-) activity in these cells.

Asparaginase↗
PubMed1975

Kniest syndrome with dominant inheritance and mucopolysacchariduria.

A mother and daughter with clinical and radiographic findings typical of the Kniest syndrome are reported. It is apparent that this syndrome is dominantly inherited and that sporadic cases may represent fresh mutations. Abnormally high keratan sulfate excretion was found, indicating that the Kniest syndrome is a mucopolysacchariduria.

Adolescent↗
PubMed1975

A new mucolipidosis with psychomotor retardation, corneal clouding, and retinal degeneration.

A man now 22 years of age had slow psychomotor development about 6 months after birth and developed intermittent corneal clouding at about 18 months. He developed truncal ataxia, hypotonia of the limbs combined with spasticity, and active deep reflexes. These have not progressed. His skeleton and facies are normal. Between his first and thriteenth year he developed sev ere optic atrophy, absence of retinal blood vessels, and an extinguished electroretinogram. Biochemical analysis of cultured fibroblasts indicated no lysosomal hydrolase deficiency; cellular metachromasia was absent and there was no mucopolysaccharidoses. Ultrastructural studies indicated single membrane vacuoles containing lamellated membranes and a polymorphous substance in tissue cultured cells and conjunctiva.

Adult↗
PubMed1974

Sanfilippo A syndrome: sulfamidase deficiency in cultured skin fibroblasts and liver.

The Sanfilippo A syndrome is an autosomal recessive mucopolysaccharidosis characterized clinically by severe mental retardation and biochemically by storage in tissue and excretion in urine of excessive amounts of heparan sulfate. Since sulfamide groups are present in heparan sulfate, a sulfamidase deficiency could explain the impaired degradation of this polysaccharide. To investigate the enzymic basis of this disease, assays for sulfamidase were performed. Extracts of cultured fibroblasts and post-mortem liver were prepared by suspension of tissues in acetate: NaCl buffer, pH 4.5, containing Triton X-100 (Rohm and Haas Co., Philadelphia, Pa.), sonication, and centrifugation at 10,000 g. The supernatant fluid was incubated with [(35)S]-N-sulfated heparin. The release of inorganic sulfate after 18 h of incubation was determined by chromatography on Sephadex G-25. The liver and fibroblast extracts of patients with the Sanfilippo A syndrome showed a deficiency of sulfamidase. The quantity of heparan sulfate in fibroblasts derived from patients with Sanfilippo A, Hurler's and Hunter's diseases was found to be 7-10%, while it was about 1.25% of the total glycosaminoglycans in fibroblasts of normal controls.

Fibroblasts↗
PubMed1973

N-acetyl-beta-hexosaminidase: role in the degradation of glycosaminoglycans.

Extracts of cultured normal human skin fibroblasts released radioactivity from a (14)C-labeled heptasaccharide prepared by addition of [(14)C]N-acetylgalactosamine to the nonreducing terminus of a hexasaccharide derived from chondroitin 4-sulfate whereas fibroblast extracts from patients with Tay-Sachs and Sandhoff-Jatzkewitz diseases did not. The results suggest that N-acetyl-beta-hexosaminidase A is responsible for degradation of the oligosaccharide substrate.

Carbohydrate Metabolism, Inborn Errors↗